<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>border</title>
    <style>
        div{
            height: 100px;
            width: 100px;
        }
        .one{
            border: 1px solid red;
        }
        .two{
            border-style: dashed;
            border-color: green;
            border-width: 5px;
        }
        .three{
            border-top: 10px solid blue;
            border-left-color: #ccc;
            border-left-style: dotted;
            border-left-width: 8px;
        }
    </style>
</head>
<body>
    <div class="one"></div>
    <div class="two"></div>
    <div class="three"></div>
</body>
</html>